In the 1970's and early 80's I had all my dental work done at Georgetown University (until they closed the dental school).
In all my years there I only had one person who I felt was not competent (especially after a comment, on a Monday morning, that he did not do Mondays well). After he treated me that day, and it was his third "oops" in about three months, I went to the head of the clinic, explained all the incidents, and that I would not want that person as my personal dentist if he were in private practive. The department head let slip that I was not the first person to complain about that student and I had a feeling that he would not graduate.
For all other work I have had done there I was very satisfied. I still have several crowns that were put on in that school and they have already exceeded the normal useful life span of a crown.
I have had several dentists since then who have commented that the crown and bridge work looked very good.
I always would bring something to read as a normal appointment would take 2-3 hours, with the sudent having to get an instructor to sign off on each intermediate step.
The most intersting day I had was when the student working on me had a problem he was not sure of what to do. By the time a decision had been made, I had been examined by five other students and three instructors. So I knew the decision was correct.
The important thing, if you go to a dental school, is to be aware that you do have a responsibility to the school to make sure they only graduate qualified students.